A conventional roller ratchet wrench is disclosed in FIGS. 9 and 10, and generally includes a base 100 which includes two recesses 101 defined in an outer periphery of a cylindrical top and an insertion 102 which is inserted in a handle 400. Each recess 101 has a pin 103 extending from an inner bottom thereof such that two pawls 200 are respectively mounted onto the two pins 103. The two pawls 200 are biased respectively by two springs 201 so as to keep them extend outward. A driving member 300 is connected to the cylindrical top of the base 100 and includes a skirt portion which has teeth 301 defined in an inner periphery thereof so as to be engaged with the pawls 200 during operation. A receiving hole 302 is defined in a top of the driving member 300 so as to receive a screw bit therein which is not shown. A ring 303 is mounted to the cylindrical top and sandwiched between the skirt portion of the driving member 300 and a flange 104 on the base 100. The ring 303 includes three notches 304 for being engaged with a bead 105 which is biased by a spring 106, and both of the spring 106 and the bead 105 are received in a hole 107 in the outer periphery of the cylindrical top. The ring 303 further includes a concaved area 305 in which the pawls 200 can be extended outward to engage with the teeth 301 of the driving member 300. When adjusting the ring 303 to position the pawls 200 out from the concaved area 305, the pawls 200 are pushed inward by the inner periphery of the ring 303 and do not engage with the teeth 301. By rotating the ring 303, the user can choose the pawls 200 to be engaged with the teeth 301 of the driving member 300. Nevertheless, when manufacturing the base 100, the two pins 103 are so tiny and close to the inside of the recess 101 so that they are difficult to be manufactured.
The present invention intends to provide an improved base structure that allows the manufacturers to easily manufacture the base by using molds with simple structure.